1 /* sys_process.c 5.8 82/12/17 */ 2 3 #include "../machine/reg.h" 4 #include "../machine/psl.h" 5 #include "../machine/pte.h" 6 7 #include "../h/param.h" 8 #include "../h/systm.h" 9 #include "../h/dir.h" 10 #include "../h/user.h" 11 #include "../h/proc.h" 12 #include "../h/inode.h" 13 #include "../h/text.h" 14 #include "../h/seg.h" 15 #include "../h/vm.h" 16 #include "../h/buf.h" 17 #include "../h/acct.h" 18 19 /* 20 * Priority for tracing 21 */ 22 #define IPCPRI PZERO 23 24 /* 25 * Tracing variables. 26 * Used to pass trace command from 27 * parent to child being traced. 28 * This data base cannot be 29 * shared and is locked 30 * per user. 31 */ 32 struct { 33 int ip_lock; 34 int ip_req; 35 int *ip_addr; 36 int ip_data; 37 } ipc; 38 39 /* 40 * sys-trace system call. 41 */ 42 ptrace() 43 { 44 register struct proc *p; 45 register struct a { 46 int req; 47 int pid; 48 int *addr; 49 int data; 50 } *uap; 51 52 uap = (struct a *)u.u_ap; 53 if (uap->req <= 0) { 54 u.u_procp->p_flag |= STRC; 55 return; 56 } 57 p = pfind(uap->pid); 58 if (p == 0 || p->p_stat != SSTOP || p->p_ppid != u.u_procp->p_pid) { 59 u.u_error = ESRCH; 60 return; 61 } 62 while (ipc.ip_lock) 63 sleep((caddr_t)&ipc, IPCPRI); 64 ipc.ip_lock = p->p_pid; 65 ipc.ip_data = uap->data; 66 ipc.ip_addr = uap->addr; 67 ipc.ip_req = uap->req; 68 p->p_flag &= ~SWTED; 69 while (ipc.ip_req > 0) { 70 if (p->p_stat==SSTOP) 71 setrun(p); 72 sleep((caddr_t)&ipc, IPCPRI); 73 } 74 u.u_r.r_val1 = ipc.ip_data; 75 if (ipc.ip_req < 0) 76 u.u_error = EIO; 77 ipc.ip_lock = 0; 78 wakeup((caddr_t)&ipc); 79 } 80 81 #ifdef vax 82 #define NIPCREG 16 83 #endif 84 #ifdef sun 85 #define NIPCREG 17 86 #endif 87 int ipcreg[NIPCREG] = 88 #ifdef vax 89 {R0,R1,R2,R3,R4,R5,R6,R7,R8,R9,R10,R11,AP,FP,SP,PC}; 90 #endif 91 #ifdef sun 92 {R0,R1,R2,R3,R4,R5,R6,R7,AR0,AR1,AR2,AR3,AR4,AR5,AR6,AR7,PC}; 93 #endif 94 95 #define PHYSOFF(p, o) \ 96 ((physadr)(p)+((o)/sizeof(((physadr)0)->r[0]))) 97 98 /* 99 * Code that the child process 100 * executes to implement the command 101 * of the parent process in tracing. 102 */ 103 procxmt() 104 { 105 register int i; 106 register *p; 107 register struct text *xp; 108 109 if (ipc.ip_lock != u.u_procp->p_pid) 110 return (0); 111 u.u_procp->p_slptime = 0; 112 i = ipc.ip_req; 113 ipc.ip_req = 0; 114 switch (i) { 115 116 /* read user I */ 117 case 1: 118 if (!useracc((caddr_t)ipc.ip_addr, 4, B_READ)) 119 goto error; 120 ipc.ip_data = fuiword((caddr_t)ipc.ip_addr); 121 break; 122 123 /* read user D */ 124 case 2: 125 if (!useracc((caddr_t)ipc.ip_addr, 4, B_READ)) 126 goto error; 127 ipc.ip_data = fuword((caddr_t)ipc.ip_addr); 128 break; 129 130 /* read u */ 131 case 3: 132 i = (int)ipc.ip_addr; 133 if (i<0 || i >= ctob(UPAGES)) 134 goto error; 135 ipc.ip_data = *(int *)PHYSOFF(&u, i); 136 break; 137 138 /* write user I */ 139 /* Must set up to allow writing */ 140 case 4: 141 /* 142 * If text, must assure exclusive use 143 */ 144 if (xp = u.u_procp->p_textp) { 145 if (xp->x_count!=1 || xp->x_iptr->i_mode&ISVTX) 146 goto error; 147 xp->x_iptr->i_flag &= ~ITEXT; 148 } 149 i = -1; 150 if ((i = suiword((caddr_t)ipc.ip_addr, ipc.ip_data)) < 0) { 151 if (chgprot((caddr_t)ipc.ip_addr, RW) && 152 chgprot((caddr_t)ipc.ip_addr+(sizeof(int)-1), RW)) 153 i = suiword((caddr_t)ipc.ip_addr, ipc.ip_data); 154 (void) chgprot((caddr_t)ipc.ip_addr, RO); 155 (void) chgprot((caddr_t)ipc.ip_addr+(sizeof(int)-1), RO); 156 } 157 if (i < 0) 158 goto error; 159 if (xp) 160 xp->x_flag |= XWRIT; 161 break; 162 163 /* write user D */ 164 case 5: 165 if (suword((caddr_t)ipc.ip_addr, 0) < 0) 166 goto error; 167 (void) suword((caddr_t)ipc.ip_addr, ipc.ip_data); 168 break; 169 170 /* write u */ 171 case 6: 172 i = (int)ipc.ip_addr; 173 p = (int *)PHYSOFF(&u, i); 174 for (i=0; i<NIPCREG; i++) 175 if (p == &u.u_ar0[ipcreg[i]]) 176 goto ok; 177 if (p == &u.u_ar0[PS]) { 178 ipc.ip_data |= PSL_USERSET; 179 ipc.ip_data &= ~PSL_USERCLR; 180 #ifdef sun 181 if (ipc.ip_data & PSL_T) 182 traceon(); 183 else 184 traceoff(); 185 #endif 186 goto ok; 187 } 188 goto error; 189 190 ok: 191 *p = ipc.ip_data; 192 break; 193 194 /* set signal and continue */ 195 /* one version causes a trace-trap */ 196 case 9: 197 case 7: 198 if ((int)ipc.ip_addr != 1) 199 u.u_ar0[PC] = (int)ipc.ip_addr; 200 if ((unsigned)ipc.ip_data > NSIG) 201 goto error; 202 u.u_procp->p_cursig = ipc.ip_data; /* see issig */ 203 if (i == 9) 204 #ifdef sun 205 traceon(); 206 #else 207 u.u_ar0[PS] |= PSL_T; 208 #endif 209 wakeup((caddr_t)&ipc); 210 return (1); 211 212 /* force exit */ 213 case 8: 214 wakeup((caddr_t)&ipc); 215 exit(u.u_procp->p_cursig); 216 217 default: 218 error: 219 ipc.ip_req = -1; 220 } 221 wakeup((caddr_t)&ipc); 222 return (0); 223 } 224